Stolen Time: The History of Tempo Rubato - Hudson, Richard 1924- (Oxford Clarendon, 1994)
Tracing the complex history of tempo rubato, this book identifies and traces the development of two main types of rubato: an earlier one in which note values in a melody are altered while the accompaniment keeps strict time, and a later, more familiar one in which the tempo of the entire musical substance fluctuates. In the course of his narrative, Hudson ranges widely over western music, from Gregorian Chant to Chopin, from C.P.E. Bach to jazz, quoting extensively from the writings of theorists, composers, and performers. In so doing he not only suggests new ways of approaching the rubato in the music of nineteenth-century composers like Chopin and Liszt, where we expect to encounter the term, but also illuminates the music of earlier and later periods, revealing its use even in the music of that most metronomic of composers, Stravinsky.